1. Technical Field
The present invention generally relates to a facsimile system having a voice data recording and transmission function, and more particularly, relates to a voice data recording and transmitting method for a facsimile unit which is linked to a personal computer.
2. Related Art
Generally, a facsimile system having facsimile and telephone functions as disclosed, for example, in U.S. Pat. No. 4,908,851 for Facsimile Apparatus Operable In Facsimile Or Conversation Mode issued to Kotani et al., U.S. Pat. No. 5,255,311 for Data Communication Apparatus issued to Yoshida, U.S. Pat. No. 5,337,349 for Image Telecommunication Apparatus issued to Furohashi et al., U.S. Pat. No. 5,337,350 for Facsimile Apparatus With Telephone System issued to Kuwahara, and U.S. Pat. No. 5,487,105 for Facsimile Apparatus Operable In Facsimile Or Telephone Mode issued to Sakai, is well known in the communication art for selectively operating either in a facsimile mode or in a telephone mode. Other facsimile systems as disclosed, for example, in U.S. Pat. No. 5,086,455 for Facsimile Arrangement Having Automatic Answering Telephone Set And Facsimile Set And Switching Process Therefor issued to Satomi et al., U.S. Pat. No. 5,131,026 for Facsimile System Having Auto-Answering Function issued to Park, and U.S. Pat. No. 5,333,179 for Facsimile Apparatus With Automatic Answering Telephone Function issued to Yamamoto et al., are constructed with an automatic telephone answering device for recording a voice message from a calling subscriber when a user is not in the vicinity of the facsimile system to answer an incoming call.
In such a facsimile system, the telephone answering device typically incorporates therein an audio recorder and related circuitry adapted for connection to local telephone lines and to the base station of the telephone. The magnetic tape recorder is programmed so that if the user does not pick up his telephone from the base station of the facsimile system during a given number of ringing bursts announcing an incoming call, a pre-recorded voice message will be sent to the caller, asking the caller to leave his/her message. After that, voice message of the caller is recorded on an audio cassette tape or semiconductor memory device depending upon whether the audio recorder is an analogue or a digital system. Voice message can also be transmitted in conjunction with image data as disclosed in, for example, U.S. Pat. No. 4,922,524 for Facsimile System With A Voice Transmission Function issued to Baba et al., U.S. Pat. No. 5,289,532 for Facsimile Apparatus With Providing Facsimile Transmission With Forwardable Voice Communication issued to Ishikawa et al., U.S. Pat. No. 5,412,710 for Facsimile Machine Capable Of Transmitting Voice Messages issued to Tanaka.
Generally, the facsimile system's control unit periodically checks if a ring signal is received from standard telephone lines of a public switched telephone network (PSTN). When the ring signal is received from the telephone lines and a calling tone (CNG) indicating that a document is being sent from another facsimile system according to a predetermined protocol recommended by the International Telegraph and Telephone Consultative Committee CCITT.30, the facsimile system receives image data in a document reception mode. At this point, a communication path is not established between the facsimile system and the telephone handset connected thereto but between a modem installed in the facsimile system and the standard telephone lines of the PSTN. Thus, if the user does not pick up the telephone connected to the facsimile system during a predetermined number of ringing bursts, an automatic answering mode is established in the facsimile system, and the user's pre-recorded voice message is sent to the caller. The caller then leaves a voice message which is, in turn, recorded on the audio cassette tape or semiconductor memory device. The link access protocol for data communications between the facsimile systems as recommended by CCITT. 30 is realized through four phases. That is, the communication line is first established between the receiving and transmitting facsimile systems, and after the CNG tone is sent to the receiving facsimile system, the receiving subscriber supplies a called station identification to the transmitting subscriber in the first phase. In the second phase, the receiving subscriber transmits a capacity identification to the transmitting subscriber, the transmitting subscriber sends command information and a phase/training signal to the receiving subscriber, and the receiving subscriber sends a ready-to-receive confirmation signal CFR. The caller's message is sent to the transmitting facsimile system at a preset communications speed in the third phase. In case that the message transmission is completed, the transmitting set sends an END signal of message transmission to the receiving subscriber, and the receiving subscriber sends a confirmation signal to the transmitting subscriber in the fourth phase.
In the conventional facsimile system having an automatic telephone answering function, the capacity of a voice storage medium into which incoming voice message is recorded is relatively small, and there is a time limit relating to the automatic telephone answering function. For instance, if the user of the telephone handset as incorporated in the facsimile system is absent for a long time period, there is no way to modify the user's voice message to be sent to several different people. Moreover, in case where the callers leave many voice messages, and the voice storage medium is full with voice messages, a new voice message cannot be recorded on the storage medium and is therefore lost at the time when voice communication is established.